Plate 15 



Fig. 1. TagelHS californianus Conrad; Jackknife clam. Fakse Bay. Natural 

 size. Exterior of left valve. 



Fig. 2. Solcn sicarins Gould ; Jackknife clam. Elkhorn Slough, Monterey Bay. 

 Natural size. Exterior left valve with extended foot. 



Fig. 3. Solen rosaceus Carpenter. San Diego. Natural size. Exterior left valve 

 with extended foot. 



Fig. 4. Siliqua patula Dixon ; Razor clam. Mouth of the Columbia River. Three- 

 .juarters natural size. Exterior of left valve with partially extended siphon. 



